What's the difference between explaining, and being defensive in customer interactions?

On the other hand, we also have a principle that tells us we should be transparent and provide information to customers, particularly when things have gone wrong. Unfortunately, explanations and being defensive can get confused.

An Example of Defensiveness vs. Explanation In Customer Service

Look at this dialogue:

Customer: "Why is it taking so long? I've been standing in line for at least 30 minutes, and I'm in a hurry"

Employee: (sounding flustered) "Well, I don't know what you want me to do about it, since we're just short staffed because of illness."

Imagine the employee using a rather plaintive and helpless voice, and it really does sound defensive, and weak, not to mention sound like an attempt to evade responsibility. This response is likely to end up escalating the interaction.

Compare:

Customer: "Why is it taking so long? I've been standing in line for at least 30 minutes, and I'm in a hurry"

Employee: "I'm sorry, but we're short-staffed, but I'll try my best to speed things up for you."

Imagine this is said calmly. It's shorter. It includes an apology, and a very very short explanation. If toned correctly, this is much less likely to come across as weak and defensive.